Why am I having these problems??

Sorry. I'm back. I am totally frustrated and don't know what to do. I can work griddlers for a while then all of a sudden the game simply locks up on me and after that I find it impossible to get it to work. I love solving griddlers as it is very calming an peaceful so having these frustrations is not a good thing for me. I'm running 64 bit windows 7. Had Java 6 - tried 7 as I thought that was the problem and things only got worse. I've put Java 6 back on but I've spent the past 2 hours trying to solve a griddler. I'm not even sure if this is an issue with the applet or something else. Tried all the browers, Firefox, Chrome, IE...cleared all their caches' restarted my computer over and over and over...

Do you have any ideas or suggestions? I would love some help with this!!